A regeneração óssea é um importante processo fisiológico e bioquímico que acontece no tecido ósseo em resposta a diferentes tipos de agressões. Sejam elas o trauma, infecções, excessos de demanda de carga, lesões expansivas, malformações vasculares e alterações metabólicas sistêmicas, em quaisquer destas situações a remodelação e regeneração óssea assumem grande importância dada a relevância do esqueleto para a saúde humana. Neste sentido, faz-se importante desenvolver técnicas de pesquisa que permita-nos estudar in vivo as alterações metabólicas que acontecem no tecido ósseo em diferentes condições. Neste sentido, nosso objetivo foi o de utilizar a técnica de cintilografia óssea para avaliar a osteogênese secundaria à osteotomia em um modelo animal de coelho da raça New Zealand. Para tanto desenvolvemos um estudo longitudinal, prospectivo, caso-controle, no qual as variáveis cintilográficas foram mensuradas tanto na pata operada (pata anterior direita) quanto na pata controle (pata anterior esquerda). A amostra foi constituída por um grupo de 10 coelhos, inicialmente, os quais foram submetidos à osteotomia, seguindo-se um período de avaliação de 12 semanas pós-operatórias, divididas em três etapas de imageamento, com 4, 8 e 12 semanas. Como resultados observamos: (A) a pata operada apresentou uma radiação externa significativamente maior do que a controle, ao uso do colimador pinhole, denotando aumento da biodistribuição e tropismo do radiofármaco para a pata operada; (B) Dentre os 3 momentos avaliados, a osteogênese foi máxima em 4 semanas e apresentou declínio significativo nas 8a e 12a semanas, denotando regeneração e resolução da lesão cirúrgica; (C) A pata controle também foi influenciada pela inatividade imposta pela pata operada. Este fato ficou evidenciado notadamente pela também redução da osteogênese na pata anterior esquerda (controle). Concluimos que a técnica da cintilografia óssea foi sensível ao diferenciar semi-quantitativamente a osteogênese na pata operada, nos três marcos temporais avaliados no presente estudo. / Bone healing is an important physiological and biochemical process that occurs in bone tissue in response to different types of aggression. Whether the trauma, infections, excessive load demand, expansive lesions, vascular malformations and systemic metabolic changes in any of these situations remodeling and bone regeneration are very important given the relevance of the skeleton to human health. In this sense, it is important to develop research techniques that allow us to study in vivo the metabolic changes that occur in the bone tissue under different conditions. In this sense, our goal was to use the technique of bone scintigraphy to evaluate osteogenesis secondary to osteotomy in an animal model of New Zealand rabbits. For this purpose we developed a longitudinal, prospective, case-control study, in which the scintigraphic variables were measured both in the operated paw (right paw) and the control paw (left paw). The sample consisted of a group of 10 rabbits, initially, which underwent osteotomy, followed by an evaluation period of 12 weeks after surgery, divided into three stages of imaging, 4, 8 and 12 weeks. As results show: (A) the operated paw external radiation was significantly higher than the control, through pinhole collimator, showing increased radiotracer biodistribution and tropism for the operated paw, (B) Among the three time intervals, the osteogenesis was maximal at 4 weeks and showed significant decline in the 8th and 12th week, showing regeneration and resolution of the surgical lesion, (C) The control paw was also influenced by the inactivity imposed by the operated leg. This fact was also evidenced by markedly reduced osteogenesis in the left paw (control). We conclude that the technique of bone scintigraphy was sensitive to differentiate semiquantitatively osteogenesis in the operated leg in three timeframes in the current study.

This thesis is an investigation of diagnostic staging and palliative radiation therapy (RT) for appendicular osteosarcoma (OSA) in dogs. Osteosarcoma is a common, highly metastatic primary bone tumour of dogs. The purpose of the first study was to assess the utility of whole body computed tomography (CT) in evaluation of metastasis in dogs with primary appendicular OSA. The objectives were to determine the utility of whole body CT as a staging tool for dogs with appendicular OSA, compare the lesion detection rate of bone scintigraphy, long bone survey radiography and whole body CT in dogs with appendicular OSA and determine the prevalence of CT-detected lung metastasis in dogs with appendicular OSA that have normal thoracic radiographs. This was a prospective cross-sectional observational study involving fifteen dogs. Test modalities were assessed against a construct reference standard for detection of bone metastasis and thoracic radiographs negative for metastatic lesions were compared against thoracic CT. Bone scintigraphy identified 5 bone lesions in 4 dogs with 2 false positive and 2 false negative results. No lesions were identified on survey radiographs or CT during blinded assessment. CT was useful for further characterizing lesions identified by bone scintigraphy. Thoracic CT identified both definitive and equivocal lesions not visible radiographically. Four dogs had equivocal ground glass pulmonary lesions on CT; 3 of these lesions progressed to radiographically discrete nodules. Overall, bone scintigraphy was the only modality that identified metastatic bone lesions. Whole body CT did not appear to be useful as alternative to bone scintigraphy; however, it may have some utility as an adjunctive diagnostic modality. Thoracic CT identified pulmonary lesions that were not visible radiographically. Ground glass pulmonary lesions in dogs should be considered suspicious for metastasis and serially monitored. The purpose of the second study was to retrospectively assess factors affecting survival time in dogs undergoing palliative RT for appendicular OSA. Fifty dogs undergoing a palliative RT protocol for spontaneous primary appendicular bone tumours were included and divided into treatment groups based on treatments administered in addition to RT. Median survival times (MST) were longest for dogs receiving RT and chemotherapy (307 days; 95%CI= 279-831) and shortest in dogs receiving RT and pamidronate (69 days; 95%CI=47-112 days). The difference in MST between dogs who received pamidronate and those who did not in this population was statistically significant on univariate (p=0.039) and multivariate analysis (p=0.0015). The addition of chemotherapy into any protocol improved survival (p<0.001). Based on the findings in this study, chemotherapy should be recommended in addition to a palliative RT protocol to improve survival of dogs with primary appendicular bone tumours. When combined with RT +/- chemotherapy, pamidronate decreased MST. / Ontario Veterinary College Pet Trust Fund

A regeneração óssea é um importante processo fisiológico e bioquímico que acontece no tecido ósseo em resposta a diferentes tipos de agressões. Sejam elas o trauma, infecções, excessos de demanda de carga, lesões expansivas, malformações vasculares e alterações metabólicas sistêmicas, em quaisquer destas situações a remodelação e regeneração óssea assumem grande importância dada a relevância do esqueleto para a saúde humana. Neste sentido, faz-se importante desenvolver técnicas de pesquisa que permita-nos estudar in vivo as alterações metabólicas que acontecem no tecido ósseo em diferentes condições. Neste sentido, nosso objetivo foi o de utilizar a técnica de cintilografia óssea para avaliar a osteogênese secundaria à osteotomia em um modelo animal de coelho da raça New Zealand. Para tanto desenvolvemos um estudo longitudinal, prospectivo, caso-controle, no qual as variáveis cintilográficas foram mensuradas tanto na pata operada (pata anterior direita) quanto na pata controle (pata anterior esquerda). A amostra foi constituída por um grupo de 10 coelhos, inicialmente, os quais foram submetidos à osteotomia, seguindo-se um período de avaliação de 12 semanas pós-operatórias, divididas em três etapas de imageamento, com 4, 8 e 12 semanas. Como resultados observamos: (A) a pata operada apresentou uma radiação externa significativamente maior do que a controle, ao uso do colimador pinhole, denotando aumento da biodistribuição e tropismo do radiofármaco para a pata operada; (B) Dentre os 3 momentos avaliados, a osteogênese foi máxima em 4 semanas e apresentou declínio significativo nas 8a e 12a semanas, denotando regeneração e resolução da lesão cirúrgica; (C) A pata controle também foi influenciada pela inatividade imposta pela pata operada. Este fato ficou evidenciado notadamente pela também redução da osteogênese na pata anterior esquerda (controle). Concluimos que a técnica da cintilografia óssea foi sensível ao diferenciar semi-quantitativamente a osteogênese na pata operada, nos três marcos temporais avaliados no presente estudo. / Bone healing is an important physiological and biochemical process that occurs in bone tissue in response to different types of aggression. Whether the trauma, infections, excessive load demand, expansive lesions, vascular malformations and systemic metabolic changes in any of these situations remodeling and bone regeneration are very important given the relevance of the skeleton to human health. In this sense, it is important to develop research techniques that allow us to study in vivo the metabolic changes that occur in the bone tissue under different conditions. In this sense, our goal was to use the technique of bone scintigraphy to evaluate osteogenesis secondary to osteotomy in an animal model of New Zealand rabbits. For this purpose we developed a longitudinal, prospective, case-control study, in which the scintigraphic variables were measured both in the operated paw (right paw) and the control paw (left paw). The sample consisted of a group of 10 rabbits, initially, which underwent osteotomy, followed by an evaluation period of 12 weeks after surgery, divided into three stages of imaging, 4, 8 and 12 weeks. As results show: (A) the operated paw external radiation was significantly higher than the control, through pinhole collimator, showing increased radiotracer biodistribution and tropism for the operated paw, (B) Among the three time intervals, the osteogenesis was maximal at 4 weeks and showed significant decline in the 8th and 12th week, showing regeneration and resolution of the surgical lesion, (C) The control paw was also influenced by the inactivity imposed by the operated leg. This fact was also evidenced by markedly reduced osteogenesis in the left paw (control). We conclude that the technique of bone scintigraphy was sensitive to differentiate semiquantitatively osteogenesis in the operated leg in three timeframes in the current study.

Os distúrbios da articulação temporomandibulares (DTM) apresentam um impacto negativo na qualidade de vida de seus portadores. A diversidade de sinais e sintomas apresentados pelos pacientes, como dores musculares, cefaléias (difusa ou localizada), dores na região da articulação temporomandibular (ATM), limitações ou excessos de abertura da boca e ruídos articulares dificultam o diagnóstico clínico. Para isso, há necessidade de uma investigação clínica minuciosa e de exames complementares. Os exames radiográficos convencionais e tomografias mostram a anatomia da região sem demonstrar alterações funcionais locais. A técnica de imagens tomográficas em Medicina Nuclear, SPECT (Single Photon Emission Computed Tomography) com 99m Tc-MDP (radiofármaco composto de Tecnécio 99 metaestável e Metileno Difosfonato), demonstra o metabolismo da região, e associada à fusão de imagens co-registradas com a tomografia computadorizada (CT), permite a localização anatômica das alterações ósseas funcionais existentes nas estruturas envolvidas. É um exame com baixa dose de radiação que possibilita a observação conjunta estrutural anatômica e metabólica. Neste trabalho avaliamos, retrospectivamente, exames SPECT/CT de 33 pacientes realizados no Setor de Medicina Nuclear do Departamento de Imagem do Centro de Tratamento e Pesquisa - Hospital do Câncer A. C. Camargo, que apresentavam sinais e sintomas de provável DTM. Os resultados dos exames foram relacionados aos dados existentes nos prontuários dos pacientes, como sexo, idade, anamnese e exame clínico. Por meio de análise descritiva, utilizando as freqüências e porcentagens das variáveis de interesse, pudemos avaliar a confiabilidade do exame. Concluímos que o SPECT/CT, quando aplicado em pacientes portadores de sinais e sintomas de DTM, apresentou alta sensibilidade (100%), especificidade (90,9%) e acurácia (96,9%), demonstrando que é um método de diagnóstico por imagem de relevância, útil e de grande valia, podendo ser um dos métodos de escolha indicados para diagnóstico de DTM. / Temporomandibular joint dysfunction play a negative role on patient life quality standard. A diversity of signs and symptoms such us muscular pain, headaches (focal or diffuse), temporomandibular joint localized pain, limitation or excessive mandibular opening and joint noise may lead to difficulties of correct diagnosis. Clinical investigation and complementary exams are necessary in these cases. Conventional radiographic and tomographic exams exactilly indicates local anatomy but do not demonstrate functional metabolic changes. Tomographic images on Nuclear Medicine, SPECT (Single Photon Emission Computed Tomography) with 99m Tc-MDP (methylene diphosphonate) a radiopharmaceutical labeled with Technetium 99m demonstrate regional metabolism changes. The association to co-registered computed tomography (CT) and image fusion allows the anatomic placement of bone functional alteration into the involved structures. SPECT/CT is a low dose radiation procedure that makes simultaneous anatomic and metabolic observation possible. This assignment was retrospectively analyzed, SPECT/CT of 33 patients from the Nuclear Medicine Sector of the Image Department of the Research and Treatment Center of the Cancer Hospital A. C. Camargo, that presented sings and symptoms of probable temporomandibular joint dysfunction. The results of the exams were related with the patient data that were on their file like sex, age, anamnesis and clinical exam. The assessment of the reliability of the exam was evaluated by descriptive analysis using frequencies and percentages of the interest variables. We conclude that SPEC/CT showed high sensitivity (100%), specificity (90,9%) and accuracy (96,9%); demonstrating that it is an important and useful diagnostic method, that may be an exam of choice to the diagnostic features of temporomandibular joint disfunction.

Os distúrbios da articulação temporomandibulares (DTM) apresentam um impacto negativo na qualidade de vida de seus portadores. A diversidade de sinais e sintomas apresentados pelos pacientes, como dores musculares, cefaléias (difusa ou localizada), dores na região da articulação temporomandibular (ATM), limitações ou excessos de abertura da boca e ruídos articulares dificultam o diagnóstico clínico. Para isso, há necessidade de uma investigação clínica minuciosa e de exames complementares. Os exames radiográficos convencionais e tomografias mostram a anatomia da região sem demonstrar alterações funcionais locais. A técnica de imagens tomográficas em Medicina Nuclear, SPECT (Single Photon Emission Computed Tomography) com 99m Tc-MDP (radiofármaco composto de Tecnécio 99 metaestável e Metileno Difosfonato), demonstra o metabolismo da região, e associada à fusão de imagens co-registradas com a tomografia computadorizada (CT), permite a localização anatômica das alterações ósseas funcionais existentes nas estruturas envolvidas. É um exame com baixa dose de radiação que possibilita a observação conjunta estrutural anatômica e metabólica. Neste trabalho avaliamos, retrospectivamente, exames SPECT/CT de 33 pacientes realizados no Setor de Medicina Nuclear do Departamento de Imagem do Centro de Tratamento e Pesquisa - Hospital do Câncer A. C. Camargo, que apresentavam sinais e sintomas de provável DTM. Os resultados dos exames foram relacionados aos dados existentes nos prontuários dos pacientes, como sexo, idade, anamnese e exame clínico. Por meio de análise descritiva, utilizando as freqüências e porcentagens das variáveis de interesse, pudemos avaliar a confiabilidade do exame. Concluímos que o SPECT/CT, quando aplicado em pacientes portadores de sinais e sintomas de DTM, apresentou alta sensibilidade (100%), especificidade (90,9%) e acurácia (96,9%), demonstrando que é um método de diagnóstico por imagem de relevância, útil e de grande valia, podendo ser um dos métodos de escolha indicados para diagnóstico de DTM. / Temporomandibular joint dysfunction play a negative role on patient life quality standard. A diversity of signs and symptoms such us muscular pain, headaches (focal or diffuse), temporomandibular joint localized pain, limitation or excessive mandibular opening and joint noise may lead to difficulties of correct diagnosis. Clinical investigation and complementary exams are necessary in these cases. Conventional radiographic and tomographic exams exactilly indicates local anatomy but do not demonstrate functional metabolic changes. Tomographic images on Nuclear Medicine, SPECT (Single Photon Emission Computed Tomography) with 99m Tc-MDP (methylene diphosphonate) a radiopharmaceutical labeled with Technetium 99m demonstrate regional metabolism changes. The association to co-registered computed tomography (CT) and image fusion allows the anatomic placement of bone functional alteration into the involved structures. SPECT/CT is a low dose radiation procedure that makes simultaneous anatomic and metabolic observation possible. This assignment was retrospectively analyzed, SPECT/CT of 33 patients from the Nuclear Medicine Sector of the Image Department of the Research and Treatment Center of the Cancer Hospital A. C. Camargo, that presented sings and symptoms of probable temporomandibular joint dysfunction. The results of the exams were related with the patient data that were on their file like sex, age, anamnesis and clinical exam. The assessment of the reliability of the exam was evaluated by descriptive analysis using frequencies and percentages of the interest variables. We conclude that SPEC/CT showed high sensitivity (100%), specificity (90,9%) and accuracy (96,9%); demonstrating that it is an important and useful diagnostic method, that may be an exam of choice to the diagnostic features of temporomandibular joint disfunction.

Bakgrund: Skelettscintigrafi är en nuklearmedicinsk undersökning. Undersökningen är den mest använda nukleardiagnostiska metoden och den genomförs ofta som en helkroppsundersökning. För att undersökningen ska kunna erhålla sin diagnostiska kvalitet, samt följa strålsäkerhetsmyndighetens rekommendationer behövs det mer kännedom till hur optimeringen ska följa as low as reasonably achievable (ALARA). Studiens syfte var att optimera patientstråldos samt att undersöka hur injicerad aktivitet kan anpassas efter patientens specifika parametrar. Metod: Studiegruppen bestod av 85 patienter som genomgick skelettscintigrafier vid Central sjukhuset i Karlstad, från perioden februari-april 2020. Resultat: Visade att både ålder och vikt är patientspecifika variabler som borde tas till betraktning vid bestämning av injicerad strålningsdos. Konklusionen: För att optimera undersökningen för varje patient bör injicerad aktivitet anpassas efter både kroppsvikt och ålder. Fler studier där andra parametrar undersöks måste genomföras. / Background: Bone scintigraphy is a nuclear medicine procedure. It is the most used nuclear diagnostic method and provides the opportunity to perform a full-body examination. For the method to retain its diagnostic quality, and to follow the recommendations of the Radiation Safety Authority, more knowledge is required on how the optimization should follow as low as reasonably achievable (ALARA). The purpose of the study was to optimize patient radiation dose and to investigate how the injected activity can be adapted to patient-specific parameters. Method: The study group consisted of 85 patients who underwent bone scintigraphy at the Central Hospital in Karlstad, from the period February-April 2020. Result: Showed that age and weight are patient-specific variables that should be considered when determining injected radiation dose. Conclusion: To optimize the examination for each patient, injected activity should be adjusted according to the patient’s body weight and age. More studies in where other parameters are investigated must be carried out.